Slide fastener with woven support tape



Jan. 6, 1970 FROHLICH 3,487,511

SLIDE FASTENER WITH WOVEN SUPPORT TAPE Filed March 1, 1967 2 Sheets-Sheet 1 A TTORAEY Jan. 6, 1970 A. FROHLICH 3,487,511

SLIDE FASTBNER WITH WOVEN SUPPORT TAPE Filed March 1, 1967 2 Sheets-Sheet 2 INVEAITOR. au-aws FRo/ /ucw 4 rmR/vsr United States Patent 3,487,511 SLIDE FASTENER WITH WOVEN SUPPORT TAPE Alfons Friihlich, Essen, Germany, assignor t Opti- Holding A.G., Glarus, Switzerland, a corporation of Switzerland Filed Mar. 1, 1967, Ser. No. 619,768 Claims priority, application Germany, Mar. 3, 1966, 0 11,485, 0 11,486 Int. Cl. AM]: 19/00 U.S. Cl. 24-2051 Claims ABSTRACT OF THE DISCLOSURE A slide-fastener assembly having a pair of slide-fastener halves, each provided with a respective longitudinally extending support tape and a respective coupling element extending along said tape and having spaced-apart heads matingly interengageable with the corresponding heads of the coupling element of the other slide-fastener half, each of said tapes being formed with a fabric tube extending therealong and provided with a respective row of openings, the coupling elements being disposed in said tubes with their heads extending through the openings of the respective row and said fabric tubes being shrunk onto said coupling elements to retain them on the respective tapes.

My present invention relates to a slide-fastener assembly having a pair of slide-fastener halves each provided with a respective support tape and a coupling element extending along an edge of the support tape for engagement with the complementary coupling element of the other tape half; the invention also relates to a method of and apparatus for making a slide-fastener assembly of this type.

The manufacture of slide-fastener assemblies by anchoring a continuous coupling element of undulating, meandering or generally helicoidal configuration to a support tape has become common in the art of syntheticresin fastener arrangements. Such systems, in which the continuous coupling element is formed with a series of spaced-apart heads interfittable with the heads in the complementary coupling element, have the advantage that they do not tend to snag as readily as slide-fastener systems using trains of individual metallic coupling elements and also provide relatively fine seams. The meandering or helicoidal coupling elements can be constituted as described in U.S. Patents No. 3,136,016, No. 3,243,489 or No. 3,267,514. While it is common to mount such coupling elements upon a fabric support tape by adhesive methods or by stitching the coupling elements to the tape (eg with a filler cord and/or bead of chain stitches) it has also been proposed to anchor the coupling elements by weaving them as warp threads in the support band, the coupling element being held in place by the weft threads. Such systems have been found to be disadvantageous in the inexactness of the positioning of the coupling element and in that the weaving system is relatively slow and painstaking.

It is, therefore, the principal object of the present invention to provide an improved slide-fastener assembly in which the coupling element has a better anchorage and more accurate emplacement with respect to the web than has been possible heretofore.

Another object of the invention is to provide an improved method of making a slide-fastener assembly in which the coupling element is anchored to a fabric tape or support band without stitching and can be joined thereto efliciently and rapidly.

Still another object of the present invention is to provide a slide-fastener assembly and method of making same whereby the coupling elements are substantially coplanar with the respective fabric webs, are firmly anchored thereto, and are concealed in major part by these tapes without causing the assembly to bulge in an unesthetic manner.

I have now found that these objects can be effectively carried out with a slide-fastener assembly Whose tapes are woven with fabric tubes or sleeves along one edge, the tubes being provided with a row of lateral openings adapted to receive the spaced-apart heads of a continuous coupling element such as one of the meandering or helicoidal coupling elements described above. The coupling element is inserted longitudinally into this tube which originally is dimensioned to have a cross-section approximately equal to or greater than that of the coupling element (facilitating longitudinal insertion of the latter), the tube being subjected thereafter to a shrinkage treatment whereby the tube condenses around the coupling element and locks the latter with the heads of the slide fastener exposed through the opening. Advantageously, the tube is formed integrally with the remainder of the fabric band, i.e. the web portion thereof, whereby the fabric band is attached to a support, and the openings are formed by omission of threads in the weaving operation, or between the threads in an open-mesh structure.

In principle, therefore, the present invention is related to the systems disclosed in my commonly assigned, concurrently filed copending applications respectively entitled Slide Fastener, Ser. No. 624,647 and Ser. No. 619,833, entitled Slide-Fastener Assembly and Method of Making Same. In the latter case, I disclose and claim a method of making a slide-fastener assembly wherein each of the fabric support tapes is formed with a row of thoroughgoing openings longitudinally of the tape while a continuous coupling element of the helicoidal or meandering type (see the aforementioned patents) is mounted upon the tape by insertion of its heads through the row of openings thus provided; the tape is thereafter subjected to a chemical or thermal shrinkage operation to condense the fabric at least in the direction of the Weft threads defining the openings to hug the heads of the coupling elements and anchor the latter to the fabric. As pointed out there, shrinkage can be effected by heat when the fabric is composed of thermoplastic threads or by chemical treatment when natural fabrics are used. Preferably, shrinkage in the weft or transverse direction of the fabric is greater than that in the longitudinal direction, while the weft threads (if thermoplastic) can be provided with formations serving as stops for the warp threads bordering these openings.

In application Ser. No. 624,647 a somewhat similar principle is applied to the formation of a slide-fastener assembly having a longitudinally extending bead serving to partly enclose the coupling element and to act as a protective member or guide for the slider. In accordance with that system, the fabric support tape of each slidefastener half is woven with warp threads running in the longitudinal dimension of the tape and weft thread transversely thereof so as to have a row of throughgoing openings along one edge of the fabric band by omission of the corresponding warp threads. At least one relatively thick flexible cord is woven, as a fillet, into the fabric adjoining the row of openings along the outer edge of the tape. The continuous coupling element of meandering or helicoidal configuration is inserted with its heads through the corresponding openings and is anchored to the tape by shrinking the fabric. Thus the beads formed by the relatively thick cords lie along respective flanks ally planar. The coupling elements may be of pear-shaped cross-section with relatively large loop-shaped heads matingly interengageable with the heads of the other coupling elements but with shanks which lie in planes perpendicular to the webs. Shrinkage is then carried out by chemical treatment when natural fibers are used, or by heat treatment when thermally shrinkable synthetic resins are employed.

In general, when shrinkage is required hereinafter both for shrinkage of the fabric and for preshrinkage of the warp threads-any conventional shrinkage step may be understood.

When the shrinkable threads are composed of natural fibers shrinkable in water or chemical solutions, the shrinking operation can involve immersion, spraying or steam treatment of the tape; for cotton-thread fabrics or cotton warp threads, treatment by immersion in aqueous caustic solutions (e.g. sodium hydroxide) is preferred. When the shrinkable threads are composed of thermally contractile fibers or filaments (e.g. nylon-type polyamides or polyesters), the treatment may involve subjecting the fabric or threads to temperatures of 180 C. to 200 C. in steam or hot air for periods of 20 seconds to 2 minutes.

According to a further feature of the present invention, the fabric tube is composed of thermoplastic or natural shrinkable fibers and is located along the edge of the band into which it is integrally woven or knitted by conventional techniques used in the production of tubular fabrics, or at a central location along the band (e.g. midway between the longitudinal edges thereof). When reference is made herein to the weaving or knitting of the tubular sleeve, it is understood that these methods include weaving techniques in which weft and warp threads are interwoven, with the warp threads running longitudinally along the plane, and the weft threads extending transversely so as to constitute the threads defining the openings through which the heads of the coil or protuberances of the coupling elements are inserted. The conventional methods may make use of circular knitting machines, socalled tube-forming needle heads for Weaving looms and the like, all being conventional in the fabric art. I have found that it is relatively simple to insert continuous coupling elements of the meandering or helicoidal type into the tube which is initially formed with a cross-section equal to or greater than that of the coupling elements, but has a shrunk cross-section less than that of the coupling elements; insertion can be effected with ease when the coupling element is enclosed at least in part or embraced in a synthetic-resin foil of channelor U- shaped configuration which opens in the direction of the head and forms a smooth surface in those regions in which the coupling element engages the fabric. Upon shrinkage of the tube, therefore, the coil is embraced in its entirety and forms a sleeve around the turns of the coupling element, thereby strengthening the anchorage.

Alternatively, a guide channel of similar cross-section can be provided in the harness of the loom, and the coupling element inserted by feeding it along this channel. According to a further feature of this invention, the weft threads between the heads of the coupling elements are thrust inwardly against a core element extending within the coupling member prior to the shrinkage of the tube, thereby positioning these weft threads between the heads of the coupling elements. This step can be carried out by bending back the fabric tube and the flexible coupling element contained therein through a relatively small radius, thereby spreading the head and enabling a toothed wheel to mesh with these heads and force the weft threads inwardly.

According to a further feature of this invention, the weft threads have only limited shrinkability or are preshrunk before they are intercolated into the fabric so that a shrinkage of or more is sustained by the weft threads in the manner previously described, thereby condensing the cross-section of the tube without materially reducing the length of the band. Some longitudinal shrinkage is, however, desirable when the heads of the coupling elements are interconnected or bear upon one another on one side and the weft threads act as spacers. In this case, the interthread spacing can be accurately established by controlled longitudinal shrinkage of the band to set the desired spread of the heads.

The core element, which can be composed of braided fabric, cords, elastomeric strands or the like, can serve as a mandrel engaged by the weft threads upon shrinkage. It has been found that the presence of such a cord, with or without the U-section foil mentioned earlier, sharply increases the strength of the anchorage. Furthermore, the fabric tubes can be made by any other method of producing fabric or fabric-like bodies from shrinkable threads. Typical methods include braiding and knotting or lace-making techniques. The fabrics and shrinkage conditions used are those described in the aforementioned copending applications.

The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is a diagrammatic perspective view, drawn to a greatly enlarged scale, illustrating a phase of the present method;

FIG. 2 is a cross-sectional view showing the relationship between the fabric tube and coupling element of the present invention after a further step in the process;

FIG. 3 is a cross-sectional view similar to FIG. 2 but showing the slide fastener in a connected condition;

FIG. 4 is a plan view diagrammatically illustrating how the coupling element is introduced into the fabric tube;

FIG. 5 is a cross-sectional view taken along the line V-V of FIG. 4;

FIG. 6 is a plan view of a spreading mechanism downstream of the insertion device of FIG. 4 in the direction of movement of the fabric;

FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG. 6;

FIG. 8 is a view generally similar to FIG. 1 but showing a knit fabric tube; and

FIG. 9 is a cross-sectional view illustrating a further embodiment of this invention.

Referring first to FIG. 3, which shows the interconnected portions of a completed slide fastener, it will be understood that a slide-fastener assembly according to this invention comprises a pair of slide-fastener halves H each provided with a respective fabric support tape 1 integrally Woven or knitted with a fabric tube 5 in which a flattened helicoidal coupling element 2 is disposed. This coupling element can have the configuration also of a meandering element and can be made as set forth in one or more of the aforementioned US. patents. In general, the coupling element is composed of a monofilamentary synthetic resin (e.g. a nylon-type polyamide) upon which the coupling heads 4 are formed by hot-die pressing or the like. The heads 4 are here shown to be molded from loops 3 which protrude from the tubes 5 and interengage at 10 (FIG. 3) so that a narrow gap 10 only is exposed. The fabric tubes otherwise fully enclose the coupling elements 2.

The heads 3, 4 of the continuous coupling element pass through openings between the weft threads of the fabric tube or through openings in the normal mesh structure of the tube whereupon shrinkage of the tube anchors the coupling element in place. A fabric, cord-like or elastomeric core 6 extends continuously through the coupling element 2 and forms a mandrel which is seized by the Weft threads 23 upon shrinkage of the tube 5 as will become apparent hereinafter. Advantageously, at least the enclosed portion of the coupling element is surrounded by a U-section channel-shaped thermoplastic synthetic-resin foil 9 which, together with the core 6, increases the grip of the tube 5 upon the coupling element.

The slidefastener assembly is manufactured, in accordance with this invention, essentially by the following steps:

(1) Initially, the fabric band 1 is woven from weft threads 7 and warp threads 8 of chemically or thermally shrinkable fiber so as to integrally form the tube 5 thereon during the fabric-making steps and by the use of conven tional tools.

(2) During the fabric-baking process, a number of warp threads may be omitted along the edge E at which the heads 3, 4 of the coupling elements are to be exposed, thereby forming openings 30 in the fabric structure as illustrated in FIG. 6 and described in the aforementioned concurrently filed copending applications. To ensure that the warp threads will shrink to a lesser extent than the weft threads during the anchoring steps, the warp threads are subjected to a preshrinking operation (ie to heat treatment or chemical treatment) by conventional means prior to intercalation into the fabric.

(3) The tube 5, during its manufacturing process, is dimensioned to have a cross-section at least equal to that of the helicoidal coupling element 2 to be subsequently introduced (FIG. 1).

(4) During the weaving operation, the helicoidal coupling element 2 is inserted into the tube 5 (cf. FIGS. 4 and 5) with or without the foil covering 9 (adapted to facilitate the feeding of the coupling element 2 into the tube 5) so that the weft threads 23 lie outwardly of the coupling element 2.

(5) Subsequently, the heads 3, 4 of the coupling elements are spread (cf. FIGS. 6 and 7) and the weft threads 23 are pushed inwardly against the core 6 which has been previously inserted (FIGS. 2, 6 and 7) into the coupling element 2 (FIG. 2).

(6) The band, Whose coupling heads 3, 4 project slightly from the tube, is then subjected to shrinkage treatment (i.e. a bath of sodium hydroxide solution when the threads are cotton, or to heating when the threads are thermoplastic), thereby shrinking the tubes 5 around the shaft portion of each coupling element so that the foil 9 and the core 6 thereof are firmly held by the shrunk tubes.

According to an important feature of this invention, the heads 3, 4 of the coupling element 2 are connected at one end or bear upon each other so as to maintain interhead gaps 31 which are established by the threads 23 disposed between the openings. The gaps between these heads are set to the predetermined width during shrinkage of the tube whereby these threads form spacers and the longitudinal shrinkage of the tube, although less than the transverse shrinkage thereof (e.g. about 5% as compared to l5% sets the coupling element in a precise fashion. In general, the threads 23 are of uniform thickness and constitute precision spacers between the heads permitting the establishment of any interhead-gap widths, merely by selection of the number of threads 23 to be disposed between each pair of adjoining heads or the thickness of these threads.

In the system of FIG. 8, the tube 105 is knitted onto the band 101 by conventional circular knitting machines or the like. In this case, the threads used for the courses and wales are of identical shrinkage characteristics and have, as the weft threads of FIGS. 1 through 3, a minimum shrinkage of about 10% in linear dimension. Upon shrinkage, the heads of coupling elements 102, which are of elliptical cross-section, are exposed. While the tubes 5 and 105 of FIGS. 1, 2, 3 and 8 are shown to be located along the edge of the tape whereby the tube 5 or 105 is located in the plane P and the major axis of the helicoidal coil coupling element 2 of elliptical crosssection is likewise located in this plane, the tube 205 of FIG. 9 is woven centrally into the tape 201; upon shrinkage of the tube 205 to the level indicated by the dot-dash line 240, the heads 203 of the coupling element 201 are exposed. The web portion 201' of this tape can be folded (201") to permit the tape half to be aflixed to a support.

The apparatus and method of the present invention is illustrated in greater detail in connection with FIGS. 4 through 7. In FIGS. 4 and 5, for example, there is represented a weaving loom 50 which forms the band 13 with a tubular sleeve 14 via a harness 51 represented in dot-dash lines. The harness 51 of the loom is provided with a bent guide channel 11 of U-shaped configuration (FIG. 5) through which the elliptical-section coupling element 12 and the core 12' are fed so that the bight portions 12" ride along the web 16 of the channel formed by this guide. The preshrunk warp threads are fed to the loom at 53. I

Downstream in the direction of movement of the fabric 13 (arrows A), there is provided a spreading device represented at 15, one of the rollers of which is illustrated at 19 in FIGS. 5 ,through 7. The roller 19 engages the back of the sleeve 14 and directs it about a center of curvature C represented by the axis of rotation of the roller 19. At the bend, a triangularly shaped knee 24 is provided with'a deflecting surface 20 about which the sleeve 14 and the coupling element 12 are sharply bent to spread the heads 17. Upon such spreading of the heads, the teeth 21 of a toothed wheel 18 in mesh with the heads 17 thrust the weft threads 23 into the roots between these heads and against the core 12. As a result, the weft threads 23 between the heads form spacers to establish the gaps 31 as previously described and are bunched in triangular or wedge-shaped bundles to retain the coupling elements with considerable strength. Downstream of the spreading device 15 and beyond the end of the channel 16, the tube passes into a shrinking stage 60 in which the fabric is contracted about the coupling elements. The shrinking system may include conveyor belts carrying the hand through a chemical-treatment zone or a throughput oven of conventional design for heat shrinkage.

The invention described and illustrated is believed to admit of many modifications within the ability of persons skilled in the art, all such modifications being considered within the spirit and scope of my invention.

I claim:

1. A method of making a slide-fastener assembly comprising a pair of slide-fastener halves each provided with a respective longitudinally extending support tape and a respective coupling element extending along said tape and having spaced-apart heads matingly interengageable with the coupling element of the other slide-fastener half, said method comprising the steps of:

(a) forming each of said tapes by providing a longitudinally extending fabric band with a longitudinal fabric tube of a cross-section equal at least to the cross-section of the respective coupling element and composed at least in part of shrinkable threads, while forming said tubes with a row of openings;

(b) inserting the respective coupling element into the respective fabric tube; and

(c) thereafter shrinking the respective fabric tube around the respective coupling element to anchor same to the tape with the heads of the coupling element projecting through said openings.

2. The method defined in claim 1, further comprising the step of surrounding at least the portions of the coupling element to be retained in the fabric tube by shrinkage thereof with a U-section foil, and inserting the foil and the coupling element concurrently into said tube whereby said foil and said coupling element are anchored in the respective tube.

3. The method defined in claim 2 wherein the threads of the fabric tube between said heads are thrust inwardly whereby said heads are exposed prior to the shrinkage of the fabric tube, and the fabric tube is thereafter shrunk about said coupling element.

4. The method defined in claim 3 wherein each tube and the respective coupling element are bent through a radius of curvature in a sense designed to spread the' heads while said threads are thrust between them. 7

5. The method defined in claim 1, further comprising the step of disposing within the interior of each of said;

coupling elements a respective core, said fabric tubes being shrunk onto said core.

6. The method defined in claim 1 wherein said tube is composed of a woven fabric having weft threads, extending transversely to said tube and lying between said openings, and warp threads extending longitudinally of said tube, said method further comprising the step of shrinking said weft threads to a greater degree than the shrinkage of said fabric threads to anchor said coupling elements in the'respe'ctive fabric tube.

7. The method defined in claim 6 wherein the warp threads of each of said tubes is shrunk prior to its intercolation in the respective tubes.

8. A fastener half for a slide-fastener assembly having two such halves symmetrically disposed for mutual engagement, comprising: 7

a support tape including a web and a tube jointly woven from weft and warp threads, said warp threads extending longitudinally of said tube, said tube having an exposed side with a row of openings formed by omission of some 'warp threads, said openings being mutually separated by intervening weft threads;

a continuous filamentary coupling element in said tube,

said element consisting of a succession of loops conforming to thecross-section of said tube and closely surrounded on all sides except said exposed side by the warp and weft threads thereof, said loops having portions projecting outwardly through said openings and forming heads engageable with fastener half; v a core inserted into said element and fitting closely within said loops while terminating short of said those of a mating heads, said intervening weft threads bearing uponanedge of said core confronting said openings; and

a U-sectionfoil open toward said row of-openings and enveloping the portion of said element occupied by said core, said foil being interposed between said loops. and the surrounding warp and weft threads of said tube. v

9. A fastener half as defined in claim 8 wherein said loops are elongate and said tube is of oblong cross-section, said openings being disposed along a narrow side of said tube. I I

10. A fastener half as defined in claim 9 wherein said core is a fiat strip extending over more than half the width of said loops in the direction of the major axis, of saidv oblong cross-section.

References Cited UNITED STATES PATENTS 

